The aim of hyperbaric oxygenation (HBO) is to increase transported oxygen in the blood over the rise of the physiologically solved part. In oral and maxillofacial surgery, treatment-resistant osteomyelitis and osteoradionecrosis are indications for HBO (according to Undersea and Hyperbaric Medical Society). Furthermore, there is an indication to apply HBO to compromised transplants of bone or soft tissue. Since 1994, 28 patients have been treated with HBO in the department of oro-, maxillofacial surgery of the Medical School Hannover. Sixteen patients had a treatment-resistant osteomyelitis. Two patients were suffering from an osteoradionecrosis in the irradiated mandible. Nine patients had received autogenous transplants, which were threatened by infection or an insufficient recipient-side. One patient was treated because of a chronic non-healing wound. In six patients we found that the chronic osteomyelitis had healed. This was proven by clinical examination and scintigraphic findings. In eight patients we had a decrease in turnover in scintigraphy and an improvement of the clinical situation. Two patients with osteoradionecrosis showed clinical improvement under HBO. In nine patients with threatened transplants we saw good healing of all critical grafts under HBO. One patient with a non-healing wound could be cured with HBO. It was shown that with HBO we could cure osteomyelitis, osteoradionecrosis and non-healing wounds to a large extent. Grafts which were threatened by infection or insufficient recipient-side healed after the application of HBO.